6 GHz envelope and RMS power detector

August 20, 2013 // By Graham Prophet
A new data sheet from Analog Devices details the ADL5511, an RF envelope and RMS detector that uses ADI's TruPwr™ technology. The envelope output voltage is presented as a voltage that is proportional to the envelope of the input signal. The rms output voltage is independent of the peak-to-average ratio of the input signal.

The RMS output is a linear-in-V/V voltage with a conversion gain of 1.9 V/V RMS at 900 MHz. The envelope output has a conversion gain of 1.46 V/V at 900 MHz and is referenced to an internal 1.1V reference voltage, which is available on the EREF pin. The ADL5511 can operate from DC to 6 GHz on signals with envelope bandwidths up to 130 MHz.

The extracted envelope can be used for RF power amplifier (PA) linearisation and efficiency enhancements and the RMS output can be used for RMS power measurement. The high RMS accuracy and fast envelope response are particularly useful for envelope detection and power measurement of broadband, high peak-to-average signals that are used in CDMA2000, W-CDMA, and LTE systems.

The ADL5511 operates from −40°C to +85°C and is available in a 16-lead, 3 × 3 mm LFCSP package. You might use it, Analog notes, in RMS power and envelope detection of W-CDMA, CDMA2000, LTE, and other complex waveforms; for drain-modulation-based power amplifier linearisation; and for power amplifier linearisation employing envelope-tracking methods.

Get the data sheet from Analog at; www.analog.com/static/imported-files/data_sheets/ADL5511.pdf